Encryption system for digital cellular communications

摘要

A system for generating a pseudo-random bit sequence (211) which may be used in enciphering digital data prior to transmission or storage of the data. The bit sequence is generated by expanding a plurality of secret key bits (205) in a manner suitable for implementation with a conventional microprocessor arithmetic logic unit (207) (ALU). The system of the present invention may be used, for example, to secure voice or data communications between a base station and a mobile station in a digital cellular communications system.